The present invention relates to a graph display apparatus and a graph display method and a program recording medium for displaying graphs corresponding to mathematical expressions.
In the related art, electronic devices called graph function calculators have been made into products. Those graph function calculators display graphs if users inputs mathematical expressions corresponding to the graphs.
It is also possible to execute graph display application programs in tablet type electronic devices such that those electronic devices display graphs according to mathematical expressions.
A graph is a visual representation of the characteristics of a function. Therefore, in learning mathematics, it is performed to change coefficient values of terms included in function expressions are changed, thereby changing the forms of graphs displayed. In a case of changing a coefficient value, it is necessary for a user to operate a graph function calculator such that the graph function calculator displays a screen for setting the coefficient value, and newly input a numerical value for the corresponding coefficient by operating keys (in a case of a tablet terminal, by operating keys of a software keyboard).
Meanwhile, it has been considered a graph function electronic calculator which displays sliders for changing numerical values, thereby enabling a user to change coefficient values of mathematical expressions by operating the sliders. However, in order to display the sliders, complicated operations are necessary.
Also, it has been considered a bar graph display method of changing a threshold value for a bar graph by a slider and redrawing the corresponding bar graph (for example, JP-A-H11-328279).
For example, a beginner in mathematics may not know what expression the beginner should input to make a graph which is a learning object be displayed in a desired form. Also, it can be considered to display a keyboard for inputting mathematical expressions on a display unit in a device such as a calculator having a restricted display area such that a user can use the keyboard to input mathematical expressions. In this case, a problem in which individual keys are small and thus are difficult to be operated occurs.
The present invention was made in view of those problems, and an object of the present invention is to provide a graph display apparatus and display method (and a program recording medium thereof) which can easily generate and display a graph in a form desired by a user.